Method and system for capture of the multi-channel image signal which can enhance the capture efficiency by deciding the unstable period of the system

ABSTRACT

The present invention relates to a system and method for capturing of the multi-channel image signal which can enhance capturing rate of image signals by exactly deciding the unstable period of an image capturing module capturing video data included in an image signal, wherein the system for capturing of the multi-channel image signal according to one embodiment of the present invention comprises a receiving module for receiving image signals including video data from at least one camera; a sync signal separating module for extracting sync signals indicating the existing location of video data from the image signal; an image capturing module for capturing video data of the image signal sequentially according to predetermined capturing order; a storage module for storing information about the unstable period of the image capturing module and the extracted sync signal respectively; and a decision module for selecting the sync signal of the second image signal located outside of the unstable period based on the extracted sync signal from the first image signal and the unstable period; wherein the unstable period includes the first unstable period, the predetermined period from failing edge of the sync signal extracted from the first image signal. According to the present invention, there is an advantage that it is possible to provide a system and a method for capturing of the multi-channel image signal which enhance the capture efficiency of image signals by raising the rate of capturable video data to the maximum through the exact decision of the unstable period of an image capturing module capturing video data of an image signal.

TECHNICAL FIELD

The present invention relates to a system and method for capturing ofthe multi-channel image signal, and more particularly, to a system andmethod for capturing of the multi-channel image signal which can enhancethe capture efficiency of image signals by exactly deciding the unstableperiod of an image capturing module capturing video data included in theimage signal.

BACKGROUND ART

Generally, an image signal capturing system is a device for receivingimage signals generated by using a photographing camera from one or aplurality of channels and converting the input image signals intodigital image signals by using an image processing board. Also, theimage signal capturing system transmits the converted digital imagesignals to a display device located in a predetermined remote site or apost-processing device such as a digital video recorder (DVR), etc forindication and storage thereof.

At this time, the image signal capturing system captures the receivedimage signals selectively according to system efficiency and importanceof a place where the photographing camera is located. That is, it isnecessary to capture more specified image signals prior to other imagesignals according to the manufacturing characteristics of the imagesignal capturing system receiving more than one image signal.

At this time, the image signal capturing system includes the unstableperiod in which the image signal capturing system cannot capture videodata of other image signals in succession soon after capturing videodata of the image signal according to the manufacturing characteristicsthereof. Accordingly, an image signal capturing operation of the imagesignal capturing system inevitably has important relation with thisunstable period.

However, there has been no system and method hereto which recognizes anddecides the unstable period correctly. Therefore, the image signalcapturing operation has been implemented on the arbitrary assumption ofthe unstable period according to a user's general experience.Consequently, the unstable period of the image signal capturing systemmay be estimated unreasonably longer than the actual time whereby thereis a problem that it is impossible to recognize a sync signal locatedoutside of the actual unstable period.

This arbitrary estimation of the unstable period yields many problemswhich cause loss of image signals and disconnection of screen of imagesignals in each channel by decreasing capturing rate of image signalsremarkably through skip of capturable video data.

Accordingly, there is a need for the advent of new concept of a systemand method for capturing of the multi-channel image signal which canenhance the capture efficiency of the image signal by deciding theunstable period of the system exactly.

DISCLOSURE OF THE INVENTION Technical Questions

The present invention is conceived to solve the aforementioned problems.Therefore, an object of the present invention is to provide a system andmethod for capturing of the multi-channel image signal which can enhancecapturing rate of image signals by raising the rate of capturable videodata to the maximum through the exact decision of the unstable period ofan image capturing module which captures video data of an image signal.

Further, another object of the present invention is to provide a systemand method for capturing of the multi-channel image signal which enablesvideo data corresponding to a sync signal under the stable state to becaptured by deciding the first unstable period and the second unstableperiod in detail based on sync signals captured by an image capturingmodule and then by letting the image capturing module recognize syncsignals only occurring outside of the first unstable period and thesecond unstable period.

Furthermore, another object of the present invention is to provide asystem and a method for capturing of the multi-channel image signalwhich can reduce loss of video data by determining an optimal capturingorder by making it possible to estimate the exact period of a syncsignal through periodical updating for the sync signal of each imagesignal.

Technical Solutions

In order to achieve the aforementioned objects, a system for capturingof the multi-channel image signal according to one embodiment of thepresent invention comprises a receiving module for receiving an imagesignal including video data from at least one camera; a sync signalseparating module for extracting a sync signal indicating the existinglocation of video data from the image signal; an image capturing modulefor capturing video data of the image signal sequentially according tothe predetermined capturing order, wherein the image signal capturedaccording to the predetermined capturing order is a first image signaland an image signal to be captured in succession after the first imagesignal according to the capturing order is a second image signal; astorage module for recording information about the unstable period ofthe extracted sync signal and the image capturing module; and a decisionmodule for selecting the sync signal of the second image signal locatedoutside of the unstable period, based on the sync signal extracted fromthe first image signal and the unstable period, wherein the unstableperiod includes the predetermined period from the falling edge of thesync signal extracted from the first image signal, i.e., the firstunstable period

Furthermore, as a technical embodiment in order to achieve theaforementioned objects, a method for capturing of the multi-channelimage signal comprises the steps of maintaining information about afirst unstable period and a second unstable period in a predeterminedstorage module; receiving an image signal including video data from atleast one channel and extracting each sync signal from the receivedimage signal respectively; capturing the video data corresponding to thesync signal of a first image signal according to predetermined capturingorder; selecting the sync signal of a second image signal having risingedge outside of the first unstable period and the second unstable periodbased on falling edge of the sync signal of the first image signal; andcapturing the video data corresponding to the sync signal of the secondimage signal; wherein the first unstable period is a predeterminedperiod from falling edge of the sync signal extracted from the firstimage signal and the second unstable period is a period from a firstpoint of time before rising edge of the next sync signal for the syncsignal of the first image signal to a second point of time after risingedge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram illustrating a system for capturing ofthe multi-channel image signal according to the preferred embodiment ofthe present invention.

FIG. 2 to FIG. 4 are drawings for explaining one example of deciding theunstable period of a decision module and selecting the sync signal of asecond image signal thereby according to the present invention.

FIG. 5 is a drawing for explaining capturing rate of an image signalcapturing system according to the present invention.

FIG. 6 is a drawing for explaining one example of decision of capturingorder according to the present invention.

FIG. 7 is a flowchart specifically illustrating a method for capturingof the multi-channel image signal according to the preferred embodimentof the present invention.

FIG. 8 is an internal block diagram of a general-purpose computer whichcan be more adopted in implementing a method for capturing of themulti-channel image signal according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a system and method for capturing of the multi-channelimage signal according to the present invention will be described indetail with reference to the accompanying drawings.

Herein, a capturing order can mean an order to capture predeterminedsync video data of a specific analog image signal and then transmit thecaptured sync video data to a post-processing device for storage orindication thereof in receiving at least one image signal, wherein afirst image signal can be an image signal including video data capturedaccording to the aforementioned capturing order and a second imagesignal can be the next image signal including video data to be capturedafter transmitting video data of the first image signal according to thecapturing order.

FIG. 1 is a configuration diagram showing a system for capturing of themulti-channel image signal according to the preferred embodiment of thepresent invention.

The system for capturing of the multi-channel image signal 100 of thepresent invention comprises a receiving module 110, a sync signalseparating module 120, a storage module 140, and a decision module 150.

First, the receiving module 110 has functions of receiving an analogimage signal from at least one camera (not shown) and outputting onlyone image signal selected by a predetermined criterion into the latterpart. That is, the receiving module 110 can be a multiplexer foroutputting the selected input signal among majority of input signals,for example, in case the receiving module 110 is a (4×1) multiplexer,the module 110 can control only one image signal among four input imagesignals to be output as shown in FIG. 1.

The sync signal separating module 120 includes a video sync separatorcircuit and is a device for extracting a sync signal from the imagesignal output from the receiving module 110. Herein, the sync signal isa standard signal for according timing with a transmitting side (acamera) in restoring the generated image signal in a camera to theoriginal image, and the sync signal is classified into a vertical syncsignal and a horizontal sync signal. The vertical sync signal includesinformation about starting point (rising edge) and ending point (fallingedge) where video data included in an image signal are located and thehorizontal sync signal includes information about duration that videodata exist. Accordingly, the sync signal separating module 120 canprepare a timing diagram about video data of the image signal as shownin (i) of FIG. 2. The sync signal can be used as data for deciding theunstable period of the image capturing module 130 and information aboutthe sync signal is stored in the following storage module 140. Theunstable period is a period for which the image capturing module 130 iswaiting for capturing video data of the next image signal (a secondimage signal) after capturing specific sync video data. Decision of theunstable period and detailed description thereof will be describedlater.

Further, the sync signal separating module 120 extracts a sync signalfrom an image signal input every predetermined period respectively,which is for correcting a minutely changed sync signal. That is, theperiod of a sync signal can be changed continuously in case ofgeneration of each image signal, e.g., according to the photographingconditions. Therefore, the sync signal separating module 120 correctsthe difference thereof and then reflects the corrected difference in theperiod of the sync signal. Accordingly, there may be an effect that thesync signal according to the present invention enables the followingdecision module 150 to decide the unstable period more exactly by makingit possible to yield the exact period of a sync signal throughcontinuous updating.

The image capturing module 130 captures specific sync video data of thesame kind or other kind of an image signal according to a predeterminedcapturing order and transmits the captured sync video data to apredetermined display device or image storage device. Also, the imagecapturing module 130 functions as an A/D converter which convertscaptured analog video data into digital video data and the module 130enables consecutive image signals to be replayed or stored bytransmitting image signals of the same kind though the same route.

The storage module 140 is a storage medium recording information aboutthe unstable period of the image capturing module 130 related to theextracted sync signal. Also, the storage module 140 can store andmaintain information about an order that the image capturing module 130captures video data of an image signal. There can be various types ofthe capturing order such as for example, a fixed type that a userdecides the order by giving predetermined weight according to importanceof a camera location (ex: A→B→C→A→B→C), or a changing type that thecapturing order of video data is decided according to a certaincriterion selected by a predetermined order decision algorism. For anexample of the changing type, there may be a case that the system forcapturing of the multi-channel image signal 100 decides an image signalcorresponding to the nearest-approaching sync signal as a second imagesignal after capturing video data of a first image signal.

The decision module 150 decides the unstable period of the imagecapturing module 130 and selects the sync signal of a second imagesignal located outside of the unstable period decided according to thecapturing order. The decision module 150 will be described by way ofprocesses of deciding the unstable period and selecting the sync signalof the second image signal according to the decision with reference toFIG. 2 to FIG. 4.

As aforementioned, the unstable period can be a period for which theimage capturing module 130 is waiting without capturing the next imagesignal (a second image signal) after capturing a first image signal. Asshown in FIG. 2 and FIG. 3, the unstable period of a predeterminedperiod can exist respectively based on the falling edge of the syncsignal (A0) of a first image signal and on the rising edge of the syncsignal (A1) of the first image signal. Accordingly, in the presentembodiment, it is noted that the unstable period output based on thefalling edge of the sync signal (A0) is a first unstable period and theunstable period output based on the rising edge of the sync signal (A1)is a second unstable period. This first and second unstable period ismanufacturing characteristics of the image capturing module 130,hereinafter how the decision module 150 decides the first and secondunstable period will be described.

FIG. 2 is a timing diagram for explaining decision of the first unstableperiod.

First, in deciding the first unstable period, the sync signal separatingmodule 120 extracts sync signals (a sync signal A0, a sync signal A1 . .. ) from A image signal of A camera and then prepares a timing diagramof sync signals as shown in (i) of FIG. 2.

Thereafter, the image capturing module 130 captures video datacorresponding to the sync signal A0 and the decision module 150 inputs atest sync signal as shown in (ii) of FIG. 2 into the image capturingmodule 130 after predetermined time passes from the falling edge of thesync signal A0 (a first step). At this time, it is preferable that thedecision module 150 controls the test sync signal to be generated forthe minimum time from the falling edge of the sync signal A0, whereinthis is in order to measure the extremely short unstable period exactly.

After input of the test sync signal, it is decided whether the imagecapturing module 130 recognizes the test sync signal (a second step).The step (the second step) is a process for deciding whether video dataof the next image are in the capturable state if the image capturingmodule 130 recognizes the test sync signal.

If the image capturing module 130 does not recognize the test syncsignal, the decision module 150 decides that the image capturing module130 is in the unstable state and repeats the aforementioned first stepand second step with increasing the input time of the test sync signalgradually (a third step). This step (the third step) is a process formaking the test sync signal having input time difference as shown in(iii) of FIG. 2 enter the image capturing module 130 in order to decidethe unstable period of the image capturing module 130 exactly. At thistime, it is preferable to minimize input time difference as much aspossible, whereby it is possible to know exactly a temporal location atwhich the first unstable period of the image capturing module 130 ends.

In the meantime, in case the image capturing module 130 recognizes thetest sync signal according to increase of input time of the test syncsignal, the decision module 150 decides the time when the relevant testsync signal is input as an ending point of the first unstable period.That is, as shown in (iv) of FIG. 2, in case the test sync signalrecognized by the image capturing module 130, for example, is a testsync signal T4, the decision module 150 can decide the interval betweenthe falling edge of the sync signal A0 and the rising edge of the testsync signal T4 as the first unstable period. At this time, the term‘recognize’ in that the image capturing module 130 ‘recognizes’ the testsync signal implies that the module 130 not only knows the fact ofoccurrence of the test sync signal, but also ‘can capture exactly’ videodata related to the test sync signal.

Accordingly, there can be an effect that the first unstable period thatmight have difference due to the manufacturing characteristics of theimage capturing module 130 is exactly decided by the decision module150.

FIG. 3 is a timing diagram for explaining decision of the secondunstable period.

First, in deciding the second unstable period, the sync signalseparating module 120 extracts sync signals from A image signal of Acamera and sync signals from B image signal from B camera and thenprepares a timing diagram of sync signals as shown in (i) and (ii) ofFIG. 3. At this time, it is supposed that the image capturing module 130captures video data corresponding to the sync signal A0 and thencaptures B image signal according to a predetermined capturing order(A→B).

The image capturing module 130 captures the sync signal A0 and thencaptures the specific sync signal of B image signal, that is a syncsignal B1 according to the capturing order. At this time, as shown in(i) and (ii) of FIG. 3, in case the rising edge of the sync signal A1 ofA image signal and the rising edge of the sync signal B1 of B imagesignal are close in aspect of time, there happens an error that theimage capturing module 130 decides the captured sync signal B1 as thesync signal A1. That is, the image capturing module 130 decides that thesync signal A1 will be generated in a predetermined sequential periodbased on the rising edge of the sync signal A1, the next sync signal ofthe sync signal A0, with reference to the timing diagram of A imagesignal. In order to prevent the error thereof, the decision module 150controls the image capturing module 130 to be in the unstable state bydeciding the sequential period based on the rising edge of the syncsignal A1 where the image capturing module 130 makes an error as thesecond unstable period. At this time, it is to set that a first point oftime is a predetermined period before the rising edge of the next syncsignal of the first sync signal and that a second point of time is apredetermined period thereafter. Therefore, it is possible to decide theperiod from the first point of time to the second point of time as thesecond unstable period. That is, the second unstable period is effectedby a temporal location of the sync signal of the first image signal andthe next sync signal of the first image signal.

For example, in case the image capturing module 130 is a video decoderchip BT878, the decision module 150 decides the former −32 horizontalsync period as the first point of time and the post +32 horizontal syncperiod as the second point of time based on the rising edge of the syncsignal A1 as shown in (iii) of FIG. 3. That is, the decision module 150can decide a 64 horizontal sync period as the second unstable periodbased on the rising edge of the sync signal A1 of (i) of FIG. 3.

Accordingly, although the image capturing module 130 tries to capturevideo data corresponding to the sync signal B1 according to capturingorder, the module 130 skips the sync signal B1 since the module 130 isin the second unstable period and captures video data corresponding tothe sync signal B2. Herein, BT878 implements function of a decoder bycapturing an image signal. And BT878 embeds a buffer for storing videodata inside and a DMA for rapidly transmitting video data to a memorymeans.

It has been experimentally proven that this second unstable period isapplied to sync signals of all image signals under the same imagecapturing module 130. That is, the second unstable period of the syncsignal A0 exists identically or similarly based on the rising edge ofall sync signals recognized by the same image capturing module 130.

Accordingly, there can be an effect that the image capturing module 130can capture only video data corresponding to a sync signal in morestable state by including the first unstable period and the secondunstable period based on the captured sync signal.

FIG. 4 is a timing diagram for explaining an example of selecting syncsignals of a second image signal according to the present invention.

The capturing order in FIG. 4 considers that video data of specific syncof B image signal are captured after video data of specific sync of Aimage signal are captured.

FIG. 4 indicates the first unstable period (f: see FIG. 2) and thesecond unstable period (s: see FIG. 3) according to the specific syncsignal recognized by the image capturing module 130 as temporallocations.

For example, as shown (i) and (ii) of FIG. 4, in case the sync signal ofA image signal and the sync signal of B image signal are input, firstly,the image capturing module 130 recognizes the sync signal A0 of A imagesignal according to the capturing order and captures the relevant videodata. At this time, it is possible to indicate the first unstable period(f) and the second unstable period (s) by the sync signal A0 as apredetermined period respectively, based on the falling edge of the syncsignal A0 and the rising edge of the sync signal A1 as shown in (iii) ofFIG. 4

Hereafter, the decision module 150 decides the sync signal of B imagesignal not having the rising edge within the first unstable period (f)and the second unstable period (s) of the sync signal A0, i.e., the syncsignal B0 as the sync signal (that is, the relevant sync signal of videodata to be captured) of the second image signal. Accordingly, the imagecapturing module 130 captures video data corresponding to the syncsignal B0.

As aforementioned, it is possible to indicate the first unstable period(f) and the second unstable period (s) by the sync signal B0 as (iv) ofFIG. 4. Likewise, it is possible to decide the sync signal A2 as thesync signal of the second image signal through the process of decidingthe sync signal of the second image signal according to the decisionmodule 150.

Accordingly, in the present embodiment, the image capturing module 130of the present invention captures video data corresponding respectivelyaccording to the capturing order as shown in (vi) of FIG. 4, i.e., inorder of sync signal A0→sync signal B0→sync signal A2 . . . .

Accordingly, there can be an effect that it is possible to capture videodata of an image signal having an improved frame rate, wherein thedecision module 150 can capture sync signals of the second image signalby recognizing sync signals exactly located outside of the unstableperiod and controls the image capture module 130 to be able to capturevideo data of the sync signal of the selected second image signal.

Hereinafter, it will be explained that the capturing rate of imagesignals is improved according to the image signal capturing system 100of the present invention in comparison with the prior art with referenceto FIG. 5.

FIG. 5 is a drawing for explaining capturing rate of image signals ofthe image signal capturing system 100 according to the presentinvention.

In FIG. 5, it is supposed that capturing order is A image signal→B imagesignal as aforementioned for the convenient understanding.

A timing diagram can be prepared as shown in (i) and (ii) of FIG. 5 byextracting each sync signal corresponding to A image signal and B imagesignal through the sync signal separating module 120.

(iii) of FIG. 5 shows the conventional unstable section, i.e., theunstable period of the image capturing module 130, wherein theconventional unstable period has been decided at his disposal by apredetermined user (for example, according to the use experience of theimage capturing module 130) through estimation about sync signals ofabout 1 or 2 period, without the correct confirmation about the actualunstable period. That is, in case the image capturing module 130captures video data corresponding to sync signal A0, the unstable periodis decided by supposing period from falling edge of sync signal A0 tofalling edge of sync signal A1 (1 period). Accordingly, an image signalcapturing operation of the image capturing module 130 according tocapturing order is to capture video data corresponding to sync signal B1after capturing video data of sync signal A0, as shown in (iv) of FIG.5. That is, the conventional image capturing module 130 does notimplement an image signal capturing operation for sync signal B0.

On the other hand, (v) of FIG. 5 is a timing diagram showing theunstable period of the image capturing module 130 according to thepresent invention, wherein the decision module 150 decides the unstableperiod of the image capturing module 130 exactly considering the firstunstable period (f) and the second unstable period (s). Accordingly, theunstable period of (v) of FIG. 5 is reduced remarkably in comparison tothe unstable period of (iii) of FIG. 5, whereby the rate that the imagecapturing module 130 recognizes sync signals increases. That is, theimage capturing module 130 captures video data corresponding in order ofsync signal A0→sync signal B0→sync signal A2→sync signal B2, etcaccording to an image signal capturing operation.

Accordingly, there is an evident tendency that the image signalcapturing rate of the present invention has improved by capturing about2 video data on the same time line compared with the conventional imagesignal capturing rate, whereby it is to implement the object of thepresent invention improving image signal capturing rate substantially.

Hereinafter, decision of capturing order of the image capturing module130 will be described with reference to FIG. 6.

FIG. 6 is a drawing for explaining an example of decision of capturingorder according to the present invention.

In capturing order of the present invention, it is possible to establisha specific capturing order according to a predetermined user, or todetermine the capturing order according to a predetermined orderdecision algorism.

First, in case of deciding the capturing order according to a user, itis possible to be made by the user's optional decision, for example, bygiving weight to a camera on the sending side where an image signal isgenerated. This decision is mainly made in case that it is necessary toreceive image signals more frequently than other image signals for highresolution of the specific image signal. Therefore, there may beprovided a predetermined capturing order deciding user interface for auser. For example, it is possible to have image signals of a bank morereceived among A image signal generated in the bank and B image signalgenerated in a general office by establishing the capturing order inA→A→B→A→A→B, since the bank is generally more important. Although thepresent invention is described by way of decision of the capturing orderby giving weight according to importance thereof, it is not definedthereto. There can be various examples of capturing order decisionaccording to a user's decision.

Furthermore, in determining the capturing order according to orderdecision algorism, for example, there may be to decide the capturingorder according to the relative starting time of other sync signal basedon one specified sync signal. As shown in FIG. 6, there is supposed thesystem for capturing of the multi-channel image signal 100 input by syncsignals of A image signal to sync signals of D image signal. The systemfor capturing of the multi-channel image signal 100 establishes syncsignal A0 of the first A image signal as a standard signal according toorder decision algorism, and sets the relative starting time of syncsignal A0 as ‘0’. Also, it is that the relative starting time for syncsignals of B image signal to D image signal is more than the relativestarting time of the standard signal. Accordingly, the image capturingmodule 130 captures video data of sync signal A0 being a standardsignal, and then captures the relevant video data by recognizing thenearest approaching sync signal D0 after falling edge of sync signal A0in aspect of time. Thereafter, order decision algorism resets syncsignal D0 as a standard signal ‘0’ and decides sync signal C1 having theminimal relative time based thereon as the next sync signal. Therefore,it is possible to determine the capturing order according to orderdecision algorism. Consequently, the system for capturing of themulti-channel image signal 100 according to the present embodiment notonly can improve capturing rate of image signals, but also can determinethe most efficient capturing order.

Furthermore, although decision of the capturing order according to orderdecision algorism of the present embodiment has been described by way ofan example that the nearest approaching sync signal to falling edge ofthe captured sync signal is decided as the next sync signal, this is forconvenient explanations. Therefore, it is also possible to analogizevarious types of order decision algorism, e.g., order decision algorismdeciding the nearest approaching sync signal occurring outside of theunstable period as the next sync signal by considering the unstableperiod of the image capturing module 130, through technical spirits ofthe present invention.

The present invention will be in detail described about an operationflow of the system for capturing of the multi-channel image signal 100.

FIG. 7 is a flowchart of an operation illustrating a method forcapturing of the multi-channel image signal according to the preferredembodiment of the present invention specifically.

The image signal capturing method according to the present embodiment isimplemented by the system for capturing of the multi-channel imagesignal 100.

First, the system for capturing of the multi-channel image signal 100maintains the unstable period of the image capturing module 130 in thepredetermined storage module 140 (S710). This step (S710) is a processfor deciding the first unstable period and the second unstable periodthrough the decision module 150 and then storing the information in thestorage module 140. As aforementioned, for example, in case of the firstunstable period, it is possible to decide the first unstable period byletting a test sync signal having predetermined time difference based onfalling edge of the captured sync signal enter (see FIG. 2) and in caseof the second unstable period, it is possible to decide a predeterminedsequence period (e.g., if BT878, 64 horizontal sync period) from risingedge of the next sync signal for the captured sync signal (see FIG. 3).

Furthermore, the system for capturing of the multi-channel image signal100 receives image signals from at least one channel and extracts eachsync signal from the received image signals (S720). This step (S720) isa process for receiving at least one image signal through the receivingmodule 110 and outputting only one image signal among received imagesignals into the latter part according to the selected criteria of thereceiving module 110. Herein, a channel may mean a communication routewhich enables an image signal to be transmitted by linking the imagecapturing module 130 with a camera generating an image signal, forexample, the channel may mean a frequency band or a frequency assignedto transmission of each image signal. Also, this step (S720) extractssync signals indicating the area where video data of received analogimage signals exist. Analog image signals comprise a large number offrames, wherein one frame comprises the blanking area and the activevideo area according to whether or not video data are included. That is,sync signals indicate the starting time, the ending time and duration ofthe active video area including video data, and it is possible toprepare a timing diagram of sync signals comprising vertical syncsignals and horizontal sync signals.

The system for capturing of the multi-channel image signal 100 capturesvideo data corresponding to the sync signal of the first image signalaccording to a predetermined capturing order (S730). This step (S730) isa process for recognizing the sync signal of the first image signal andcapturing video data corresponding thereto through the image capturingmodule 130.

Furthermore, the system for capturing of the multi-channel image signal100 selects the sync signal of the second image signal based on fallingedge of the sync signal of the first image signal (S540). This step(S540) is a process for selecting the sync signal of the second imagesignal to be captured after the first image signal through the decisionmodule 150. That is, the decision module 150 selects a sync signal nothaving rising edge within the first unstable period and the secondunstable period of the sync signal of the captured first image signal asthe sync signal of the second image signal based on capturing order. Theexplanation related thereto has been already aforementioned (see FIG.4).

The system for capturing of the multi-channel image signal 100 capturesvideo data corresponding to the sync signal of the second image signal(S750).

Accordingly, the method for capturing of the multi-channel image signalaccording to the present embodiment decides the unstable period of animage signal exactly whereby there is no more optional decision aboutthe unstable period. Therefore, there can be an advantage that it ispossible to improve capturing rate of image signals by making itpossible to capture video data of the existing uncapturable imagesignal.

The embodiments of the present invention include computer readable mediaincluding program instructions to implement various operations embodiedby a computer. The media may also include, alone or in combination withthe program instructions, data files, data structures, tables, and thelike. The media and program instructions may be those specially designedand constructed for the purposes of the present invention, or they maybe of the kind well known and available to those having skill in thecomputer software arts. Examples of computer-readable media includemagnetic media such as hard disks, floppy disks, and magnetic tape;optical media such as CD-ROM disks; magneto-optical media such asfloptical disks; and hardware devices that are specially configured tostore and perform program instructions, such as read-only memory devices(ROM) and random access memory (RAM). The media may also be atransmission medium such as optical or metallic lines, wave guides, etc.including a carrier wave transmitting signals specifying the programinstructions, data structures, etc. Examples of program instructionsinclude both machine code, such as produced by a compiler, and filescontaining higher level code that may be executed by the computer usingan interpreter.

FIG. 8 is an internal block diagram of a general-purpose computer whichcan be more adopted in implementing the method for capturing of themulti-channel image signal according to the present invention.

The computer system 800 includes any number of processors 810 (alsoreferred to as central processing units, or CPUs) that are coupled tostorage devices including primary storage (typically a random accessmemory, or “RAM 820”), primary storage (typically a read only memory, or“ROM 830”). As is well known in the art, ROM 830 acts to transfer dataand instructions uni-directionally to the CPU and RAM 820 is usedtypically to transfer data and instructions in a bi-directional manner.Both of these primary storage devices may include any suitable type ofthe computer-readable media described above. A mass storage device 840is also coupled bi-directionally to CPU and provides additional datastorage capacity and may include any of the computer-readable mediadescribed above. The mass storage device 840 may be used to storeprograms, data and the like and is typically a secondary storage mediumsuch as a hard disk that is slower than primary storage. A specific massstorage device such as a CD-ROM 860 may also pass data uni-directionallyto the CPU. Processor 810 is also coupled to an interface 850 thatincludes one or more input/output devices such as such as videomonitors, track balls, mice, keyboards, microphones, touch-sensitivedisplays, transducer card readers, magnetic or paper tape readers,tablets, styluses, voice or handwriting recognizers, or other well-knowninput devices such as, of course, other computers. Finally, processor810 optionally may be coupled to a computer or telecommunicationsnetwork using a network connection as shown generally at 870. With sucha network connection, it is contemplated that the CPU might receiveinformation from the network, or might output information to the networkin the course of performing the above-described method steps. Theabove-described devices and materials will be familiar to those of skillin the computer hardware and software arts.

The hardware elements above may be configured to act as one or moresoftware modules for implementing the operations of this invention.

The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteaching.

Therefore, it is intended that the scope of the invention be defined bythe claims appended thereto and their equivalents.

Although the present invention has been described in connection with theembodiment of the present invention illustrated in the accompanyingdrawings, it is not limited thereto since it will be apparent to thoseskilled in the art that various substitutions, modifications and changesmay be made thereto without departing from the scope and spirit of theinvention.

INDUSTRIAL APPLICABILITY

According to the present invention, it can be provided a system and amethod for capturing of the multi-channel image signal which can enhancethe capture efficiency by raising the rate of capturable video data tothe maximum by deciding the unstable period of an image capturing modulecapturing video data of an image signal.

Furthermore, according to the present invention, it can be provided asystem and a method for capturing of the multi-channel image signalwhich can capture video data corresponding to a sync signal under morestable state by deciding the first unstable period and the secondunstable period in detail based on sync signals captured by an imagecapturing module and by enabling sync signals only occurring outside ofthe first unstable period and the second unstable period to berecognized by the image signal module.

Furthermore, according to the present invention, it can be provided asystem and a method for capturing of the multi-channel image signalwhich can reduce loss of video data by determining the optimal capturingorder by making it possible to yield the exact period of the sync signalthrough periodical updating for the sync signal of each image signal.

1. A system for capturing of the multi-channel image signal, the systemcomprising: a receiving module for receiving image signals includingvideo data from at least one camera; a sync signal separating module forextracting sync signals indicating the existing location of video datafrom the image signal; an image capturing module for capturing videodata of the image signal sequentially according to a predeterminedcapturing order wherein an image signal captured according to thecapturing order is a first image signal and an image signal to becaptured after the first image signal is a second image signal; astorage module for storing information about the unstable period of theimage capturing module and the extracted sync signal respectively; and adecision module for selecting the sync signal of the second image signallocated outside of the unstable period based on the sync signalextracted from the first image signal and the unstable period; whereinthe unstable period includes the first unstable period, predeterminedperiod from falling edge of the sync signal extracted from the firstimage signal.
 2. The system as claimed in claim 1, wherein the firstunstable period is decided by implementing the steps of: a first step ofinputting a test sync signal into the image capturing module afterpredetermined time elapses from the falling edge of the sync signal ofthe first image signal; a second step of deciding whether the imagecapturing module recognizes the test sync signal; a third step ofrepeating the first step and the second step with increasing thepredetermined time until the test sync signal is recognized; and afourth step of deciding a period from the falling edge to the time atwhich the third step ends as the first unstable period.
 3. The system asclaimed in claim 1, wherein: the unstable period further comprises thesecond unstable period from the first point of time before the risingedge of the next sync signal for the sync signal of the first imagesignal to the second point of time after the rising edge; wherein thedecision module selects the sync signal of the second image signal basedon the first unstable period and the second unstable period.
 4. Thesystem as claimed in claim 3, wherein: the decision module selects thesync signal of the second image signal having rising edge outside of thefirst unstable period and the second unstable period; wherein the imagecapturing module captures video data of the second image signalcorresponding to the selected sync signal.
 5. The system as claimed inclaim 1, wherein the predetermined capturing order is determinedaccording to a user or predetermined order decision algorism.
 6. Thesystem as claimed in claim 6, wherein the sync signal separating moduleextracts sync signals from the image signal every predetermined periodrespectively.
 7. A method for capturing of the multi-channel imagesignal, comprising the steps of: maintaining information about the firstunstable period and the second unstable period of an image capturingmodule in a predetermined storage module; receiving image signalsincluding video data from at least one channel and then extracting eachsync signal from the received image signals respectively; capturing thevideo data corresponding to a sync signal of a first image signalaccording to predetermined capturing order; selecting a sync signal of asecond image signal having rising edge outside of the first unstableperiod and the second unstable period based on falling edge of the syncsignal of the first image signal; and capturing the video datacorresponding to the sync signal of the second image signal; wherein thefirst unstable period is a predetermined period from falling edge of thesync signal extracted from the first image signal; and the secondunstable period is a period from the first point of time before risingedge of the next sync signal for the sync signal of the first imagesignal to the second point of time after rising edge.
 8. A computerreadable recording medium recording a program for implementing themethod of claim 7.